This invention is directed to a radio-frequency (RF) probe or handpiece for use with and for controlling an electrosurgical instrument or apparatus.
Electrosurgical instruments are well known and widely used in the medical, dental, and veterinarian fields. They offer the capability of precision cutting and coagulation with electrosurgical currents preferably in the megacycle range using a handpiece with, for example, removable needle, ball, or loop electrodes in a unipolar operating mode or with a forceps in a bipolar operating mode. Ellman International, Inc. makes available an electrosurgical instrument for Radiosurgery which provides on its front panel connectors for receiving the plug of a cable-connected unipolar handpiece and a ground or indifferent plate, as well as connectors for receiving the plug of a cable-connected bipolar electrode. One form of such an instrument is described in U.S. Pat. No. 5,954,686, whose contents are incorporated herein by reference. Such instruments are characterized by different modes and sub-modes of operation. For example, the instrument described in the patent, which is typical of other similar instruments, has a cutting mode, separable into CUT and CUT/COAG sub-modes, and a coagulation mode, separable into HEMO, FULGURATE, and BIPOLAR sub-modes.
In a typical surgical setting using such an instrument, a surgeon may first use a handpiece while the instrument is in its cutting mode to perform a desired cutting procedure and then desire to use the same handpiece for coagulation of blood vessels while the instrument is in its coagulation mode. To this end, the electrosurgical instrument has on its front panel push buttons or switches for activating internal circuitry for switching the electrosurgical instrument from its cutting to its coagulation mode or vice-versa. A current electrosurgical instrument contains a power-supply-controlled radio-frequency (RF) oscillator which generates RF currents typically in the megacycle range as high-frequency AC waves. For most cutting purposes, the AC waveform is fully filtered to produce an approximate DC waveform. For most coagulation purposes, the AC waveform is partially rectified (commonly half-wave rectification) to produce the characteristic half-wave rectified waveform. This is accomplished by switching in certain rectifier and filter components for the cutting mode, and switching in certain rectifier components for the coagulation mode. This is well known in the art and further description is unnecessary. Suffice to say, the switching action occurs inside the instrument when the front panel controls are activated by the surgeon.
To simplify mode selection by the surgeon, it is known to place on the handpiece two finger-activated switches that can be connected by appropriate wiring to the electrosurgical instrument and wired in parallel with the front panel switches so that activation of either the finger switches on the handpiece or the front panel switches will allow mode selection. This is similar to the connection and operation of a foot switch that can be used by the surgeon to activate and deactivate the RF currents. More modern electrosurgical instruments, however, do not lend themselves to such a simple approach. The typical modem electrosurgical instrument is computer-controlled, typically by a microcontroller (xcexcC); hence simple parallel-connected circuitry may not work satisfactorily. Another problem is that the standard handpiece has only three terminals, one of which is dedicated to carrying the high-frequency or RF electrosurgical currents; hence, mode selection must be carried out in a safe manner using only two of the three terminals.
A further complication in the use of such instruments is the variety of surgical procedures to which the instrument can be applied, often with different electrodes. Each surgical procedure typically requires not only a particular electrosurgical mode, such as cut or cut/coag, or hemo, but also may require a different set of mode conditions, such as the power setting and/or a different time duration of power application. Each typically requires a different electrode. The Ellman company, as an example, offers between 50 and 100 different electrodes including shapes and sizes for the various medical specialties.
With four therapeutic waveforms available in current Radiosurgery instruments and a wide power range, it is time consuming and memory dependent on the part of the surgeon and or staff to choose and mount in the handpiece an electrode for the desired procedure, and then tune in the correct waveform and power settings for the particular procedure to be carried out. Also there may have been occasions when electrosurgical injuries or increased recovery times may have occurred due to the choice of the electrode used as well as incorrect waveform settings and incorrect power settings for the chosen procedure.
A principal object of the invention is a handpiece for an electrosurgical instrument for use by the surgeon whose choice depends primarily on the surgical procedure to be employed.
Another object of the invention is a handpiece for an electrosurgical instrument that eliminates or reduces the chance of the surgeon choosing the incorrect or less than optimum electrode for the surgical procedure to be employed.
A further object of the invention is a handpiece in which the choice of the handpiece controls the operating mode of the instrument, preferably, also the mode conditions, that is desired for carrying out a particular procedure.
These objects are achieved in accordance with one aspect of the invention by a novel handpiece construction comprising an electrode that is permanently attached or mounted to the handpiece. In a preferred embodiment, the surgeon has available a family of such handpieces each configured and adapted for either the same procedure, as for example different shapes or sizes of electrodes, or for a different procedure in the surgeon""s specialty. So, for example, if procedure A is to be carried out, then handpiece A is selected which includes the electrode that the surgeon deems best for that procedure. Similarly, if procedure B is to be carried out, then handpiece B is selected which includes the electrode that the surgeon deems best for procedure B. Fewer electrode errors are possible, in another preferred embodiment, because the handpiece may be labeled for that procedure or otherwise visually distinguishable from other handpieces, as, for example, by shape or color-coding, and the optimum electrode for that procedure is already pre-attached to the handpiece. While this arrangement seems to imply greater cost, as multiple handpieces are required to cover all the procedures that the surgeon typically performs, the cost to manufacture each handpiece is far below that of the standard handpiece and so the overall cost may not be significantly greater, keeping in mind the comfort of knowing that errors are less likely to occur.
In a further preferred embodiment of the invention, to further reduce costs, the handpiece comprises a common connector attached at one end to a cable terminating in an instrument end connector for attachment to the instrument, and at its other end adapted to receive and hold and electrically connect to the handpiece proper itself, meaning a handle for the surgeon to hold and the attached electrode. Each member of the family of handpieces are preferably configured to removably attach to the common connector and thus could use the same common connector and cable and end connector for connecting to the instrument as the source of RF electrosurgical currents. As a result, the user need purchase only one common connector/cable accessory usable with any of the handpiece family members.
For convenience of explanation, xe2x80x9chandpiece sectionxe2x80x9d as used herein shall mean the removable handles each holding an electrode, xe2x80x9ccable-connector sectionxe2x80x9d shall mean the common connector for the handles, attached cable, and end connector for the instrument, and xe2x80x9chandpiecexe2x80x9d or xe2x80x9cprobexe2x80x9d shall mean the combination of the two sections making up a working unit.
In the copending referenced application (PAT112), whose contents are herein incorporated by reference, dedicated handpieces are described that incorporate a electrical component, such as an impedance (resistor, capacitor, inductor, transistor or IC), a microprocessor or microcontroller, or storage means such that the handpiece generates a unique control signal that when processed by a microprocessor or microcontroller in the electrosurgical instrument will automatically select that particular set of mode conditions specific to the procedure to which the handpiece is dedicated, the mode conditions including a desired RF current mode as well as operating conditions such as power. The handpieces of this invention are uniquely suited to incorporate the invention of the copending application as each handpiece here already has an electrode pre-attached so it is only necessary to incorporate in the handpiece the appropriate electrical component to implement the invention of the copending application when it is combined with an electrosurgical instrument containing the means to interpret and implement the dedicated handpiece concept.
As a further feature of the invention, the appearance of the handpiece is controlled, as for example, by color-coding or by its shape, so that the surgeon understands that a specific colored or shaped handpiece is associated with a specific procedure, which will further minimize the possibility of surgeon error. As an additional feature, the shape of the handpiece can be related to the position of the electrode so that the surgeon can tell by the position of the handpiece in his hand the orientation of the electrode at the patient""s tissue.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described the preferred embodiments of the invention, like reference numerals or letters signifying the same or similar components.